In the present scenario, more than 80% of air filter's life cycle cost is an energy cost, which is due to an extra energy consumed by a driving fan to overcome a pressure drop of an air stream flowing across the air filter while maintaining a designated air flow rate. It has been observed that, higher is a filtration efficiency of the air filter, greater is the pressure drop across the filter thereby resulting in higher consumption of the energy.
Today, every building equipped with a centralized air conditioning has one or more air filters in each of their air handling units, indicating that air filtration plays an important role in indoor environmental quality as well as taking a significant portion of energy consumption in the buildings. High efficiency air filtration is also essential in semiconductor and pharmacy manufacturing industries as well as medical facilities. High Efficiency Particulate Air (HEPA) filter often includes densely packed fiber material, which is both cost and energy expensive.
The Air filter generally has a lower filtration efficiency on smaller particles, which has a more significant impact on health and on manufacturing processes that require clean air environment. To effectively remove these very fine particles, densely packed filter media is usually used, which results in high pressure drop across the filter. High efficiency air filter generally has a higher filtration efficiency on particles with size larger than 1 micrometer than the value indicated by the efficiency rating of the High efficiency air filter.
There have been efforts made in the past on refining the micro and mini structure of air filter to reduce the pressure drop. However, due to the physical limits of fluid mechanics, there still exists a long-standing need for improved systems/devices and methods that facilitates in further reduction of the pressure drop, especially in high efficiency air filters.